Thomas Parran was an American physician and Public Health Service officer. He was appointed the sixth Surgeon General of the United States from 1936 to 1948, and oversaw the notorious Tuskegee syphilis experiment and Guatemala syphilis experiment.

The surgeon general of the United States is the operational head of the United States Public Health Service Commissioned Corps (PHSCC) and thus the leading spokesperson on matters of public health in the federal government of the United States. The surgeon general's office and staff are known as the Office of the Surgeon General (OSG), which is housed within the Office of the Assistant Secretary for Health.